The idea to build toilets and a servery in St Gregory’s Church, Sudbury – which dates back to 1150 - was first discussed around 25 years ago.

Building work, now due to begin at the end of June, will also see the vestry completely refurbished to provide much needed storage space.

The £200,000 project has taken five years to plan, fund and obtain the necessary permissions.

It is expected to take five months to complete.

St Gregory’s has a regular congregation of 130 parishioners, and around 6,000 people use the church each year for events.

Some historians believe St Edmund was crowned king of East Anglia in the church, which also attracts casual visitors who come to see Simon of Sudbury’s head displayed in the vestry.

But the building has no toilet facilities, so elderly congregation members currently have to walk more than 100 yards and cross a busy road to get to the church hall on the corner of Prince Street.

To mark the start of the scheme, a day of celebrations will take place on June 7 where detailed plans for the refurbishment will be on display.

Reverend Canon Gregory Webb said: “The church has been blessed by generous legacies and donations from the congregation to pay for the building work, and support for the celebrations has been given willingly by many local businesses.

“We hope many people will visit the church to look at the plans and join the celebrations.”

These include a fundraising tea party in the church from 3pm and a gala organ recital at 6.30pm.